The invention relates generally to power-driven conveyors and more particularly to conveyor systems using sensing elements embedded in a conveyor body to detect conditions affecting the conveyor.
Sensors embedded in conveyor belts and other kinds of conveyors with moving article-supporting conveying bodies require power to make sensor measurements and to transmit measurements off the belt. On-belt batteries, storage capacitors, and energy-harvesting devices have been used or proposed for that purpose. But most of these solutions require recharging or replacement, take up space, add weight, or weaken the belt. Rip detectors are used in flat belts to determine if a belt has developed a tear and is in danger of imminent failure. Many rip detectors include thin wire loops embedded in a belt. When an untorn, closed wire loop passes a detector along the conveying path, a detection signal is generated and detected by the detector. When a torn, open wire loop passes, the detection signal differs from that for an untorn loop, indicating a rip in the belt. Although these devices do not require on-belt power sources, they are not designed to make a continuum of sensor measurements. Rather they generate a detection signal that is used for a binary conclusion: torn or not torn.